Object location relay system



Oct. 13, 1953 E. M. WILLIAMS OBJECT LOCATION RELAY SYSTEM Filed March 6, 1945 7 Sheet s-Sheet l Oct. 13, 1953 E M wlLLlAMS 2,655,649

OBJECT LOCATION RELAY SYSTEM Filed March 6, 1945 7 sheets-sheet 2 I I I I I MHV/75756 INVENTOR. Vif/9,60 fz Maw/VJ Oct. 13, 1953 E M, W|| |AMS 2,655,649

OBJECT LOCATION RELAY SYSTEM Filed March e, 1945 7 sheets-sheet s Z0 2/ 2z 23 2f ne/ff mamme myn/:MMM ggf f a l b t /z- 3g naaf nA/:wwf

.1w/rm 0am asc/Mme J :fraz/ff 0\ Oct. 13, 1953 E. M. WILLIAMS 2,655,649

OBJECT LOCATION RELAY SYSTEM Filed March 6, 1945 7 Sheets-Sheet 4 BY Ontw-@M 9. #.14

Oct. 13, 1953 E. M. WILLIAMS 2,655,649

OBJECT LOCATION RELAY SYSTEM Filed March 6, 1945 7 Sheets-Sheet 5 Oct. 13, 1953 E. M. WILLIAMS 2,655,649

OBJECT LOCATION RELAY SYSTEM Filed March 6, 1945 7 Sheets-Sheet 6 Oct. 13, 1953 E, M, wlLLlAMs 2,655,649

' OBJECT LOCATION RELAY SYSTEM Filed MarCh 6, 1945 7 Sheets-Sheet BY @ff/@ @4a.

Patented Oct. 13, 1953 UNITED STATES PATENT OFFICE 6 Claims. (Cl. 343-6) (Granted under Title 35, U. S. Code (1952),

sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

`This invention relates to a radio system and more particularly to a radio system for the long distance control and direction of an object 1n flight.

The objects of the present invention comprise the provision of an improved means for the long distance control and direction of an object in flight; an improved device comprising means for relaying to a ground control station, range and azimuth information regarding the position at any desired time of the object in flight; an improved means for imparting substantially accurate information to the ground control station of, and for maintaining from the ground control. station control over, the direction, speed and. alti tude of the object in flight; and a radio remote control system that very largely overcomes jamming interference and that operates at ultra-high frequencies.

With the above and other objects in View which will be apparent to those who are informed in the field of radio controlled objects in night from the following description, suitable illustrative embodiments of the present invention are shown in the accompanying drawings, wherein:

Fig. l is a diagrammatioal presentation of the major overall radio elements of the present invention;

Fig. 2 is a diagrammatical presentation of the major overall physical elements of the present invention with the directional and range indieating concept forming parts thereof;

Fig. 3 is a block diagram of a radio circuit in the relay station portion of the present system; Fig. 4 is a presentation of the radiated pulse envelope that is emitted by the relay circuit that is shown in Fig. 3;

Fig. 5 is a block diagram of a modification in the circuit that is shown in Fig. 3;

Fig. 6 is a partly block diagram and a partly schematic diagram of a circuit at the control station for converting the output of a receiver part of the circuit back to the original azimuth reading;

Fig. 7 is a re-presentation of the signals from a receiver part of the circuit that is shown in f Fig. 10 is a fragmentary modification in the circuit that is shown in Fig. 6.

The overall assembly that is contemplated in the present invention comprises broadly a control station I, a preferably airborne relay station 2 and an object 3 in flight, such as a missile or the like.

The control station I is assumed to remain in a fixed position and is provided with two radar antenna systems, the radar antenna assembly 4 transmitting and receiving signal on a frequency F1 and the radar antenna assembly 5 receiving signal on a frequency F2.

The relay station 2 is preferably supported in the air in any desired manner, as by a balloon 8 that is attached thereto by a tie 9, or the like. The relay station 2 comprises a transpondor beacon ID on the frequency Fi and a transpondor beacon II on the frequency F2 that are adapted for being in communication with the control station I, and with the object 3 in flight. The beacon IU is preferably provided with two antennas one directed in the general direction of the control station, the other in the general direction of the missile as shown. Alternatively a single omnidirectional antenna may be provided. Similar provision is made for beacon I I.

The obj ect in flight 3 is provided with a receiver I4 operating on the frequency F1 and an interrogator-transmitter receiver I3 that is operating on the frequency F2. The course of the objectin-fiight 3 is directed away from both the control station I and the relay station 2, as indicated by the arrow I6.

The present system is designed for overcoming the major problem that is encountered in working with long-range guided missiles that have been controlled heretofore by radio signals that have been at the low frequencies necessary for propagation over the required range and that are not adequately accurate and that are easily jammed by interfering radio signals. In the present system a very high frequency, that is substantially of three thousand megacycles, or higher, is used.

In the operation of the present system, a small, lightweight relay station 2 is released preferably from the missile 3 at a desired point between the control station I, from which the operation is started, and an intended target. The relay station 2 serves to pass back to the control station I information regarding the range and azimuth of the missile 3 during its course of flight and also to change the direction of flight, speed and altitude of the missile 3 as dictated by control impulses that are received by the relay station 2 from the ground control station I.

The missile 3, within a hatch of which the relaying units are releasably disposed, is launched from the ground control station I and is initially controlled by a magnetically monitored gYIO- compass, and as to its. altitude by abarometric altimeter, as are well known in the art.

A parachute, not shown, that carries the relaying units inclusive of the balloon 8 in deflated condition, is released in known manner from the. hatch part of the missile 3, at a point determined by an airlog at the ground controlv station If. As soon as the parachute-carried relay 2 is cleared by the missile 3, the self-erecting balloon 8-A is' inflated automatically. The balloon 8 becomes; erected and carries the relay station 2 to. an altitude that is determined by a preset barometric; device in known manner. This altitude preferably is as high as is practicable.

After the release of' the relaying units by the missile 3, the missile 3 may be caused todescend automatically to a lower' altitude so that it can befplaced accurately upon a desired target.

The beacons IG and II", carriedby the relay station 2, are relativelyv non-directional but are oriented in azimuth by a magnetic-compass-controlled gyro, not shown, within the relay station 2;, in known manner, or disposed verticallyy for omnidirectional' use. The gyro may' actually rotatel the entire relayu station until its aspect gives optimum operation.

Interrogator I3 on missile 3: sends out interrogation pulses at a regular pulserecurrence rate and' over a conical scan until?, in the process of scanning., it receives the beacon pulse from beacon I'I at the relay station 2. The beacon II transponds at a slightly different frequency from that transmitted by the interrogating transmitter I3 so that nothing except beacon II will cause a response thereto.

The interrogator I3 homes on the beacon impulse whenpicked up and switches to a` second mode of operation in which the-pulse recurrence frequency is unlocked and is arranged so that each outgoing pulse follows directly upon each pulse received from the bea-con I I. In this manner' the spacing between pulses is twice that correspond-ingA toy the range between missile 3 and relay station 2. The transpondor pulses are also transmitted from the relay beacon I I in the other direction and are` received at the ground: control station I and the range between the relay station 2 and the missile 3 is determined" from these pulses in known manner.

The scanning dish of 'mterrogator 1.3 is provided with a magnetic compassl comparison device 26 shown in Fig. 3, which provides. for the determination of the azimuth bearing of the relay station 2 with respect to the missile 3'. This comparison device develops a signal which, i'n turn, codes; the interrogating pulse from the scanner I3. A preferred method of coding the interrogating pulse will be described hereinafter.

The interrogating transmitter I3 will cease to key in its second mode if it fails to` receive in usual manner a single beacon pulse from the relay beacon II. In the event that a beacon pulse from beacon II fails to be received by interrogator I3, a time delay occursl and then interrogator I3." is switched back by known means to its first mode of opera-tion or to its regular pul'se recurrence rate and if beacon pulses still are not received, after a second time delay, the interrogator I3 returns to scan.

rIhe interrogator I3 uses a usual form of lobeswitching and homes on the beacon impulses from the relay beacon I I in both the first and the second modes of operation. The dishes of receiver I4 and of the interrogator I3 of the F1 and the F2 systems, respectively, on the missile 3 move in synchronism, both being. controlled. by F2. system.

The radioreceiver I4iof the frequency F1 is provided on missile 3 for receiving beacon impulses i from beacon I0 of the frequency F1 on relay station 2. Relay beacon I0, of frequency Fi, responds to radar 4 at the ground control station I. Radar. 47 atthe control station I is used, by means of. a pulse recurrence frequency control that is well known to the art, to apply impulses for controlling the flight of the missile 3 through the frequency F1 beacon` l0 on the relay station 2 and receiver I4. This control governs the azimuth, altitude, throttle, dumping, etc. of the missile 3.

In the. relay station 2, the F1 beacon I0 is a standard type, beacon that feeds signals to` the ground control' station I` and to the missile 3. The signalv of the Fi beacon IIII is coded according to, the azimuth code that: is received on the- F2 relay beacon I I from the F2 transmitter of interrogator I3 on the missile 3'. By so operatingthe signal on the F2 beacon supplies azimuth infor'- mation to the radar receiver 5. at the ground-,corrtrol station I. By responding to the pulse recurrence rate changes on the Fi frequency, the signal on there beacon enablesthe controls to be applied to the missile 3.

The radar 4 at` the controly stationv I is lobeswitched for high angle accuracy, transmits on F1. frequency and receives the response from the relay F1 beacon` I0, on aY slightly different frequency so, that, ordinary echoes do not appear. The dish of the F2 receiver 5l on the controlstation I is synchronizedy inv position with. the, dish of theV control. station radar 4.. 1Ihe. F2 receiver 5 receives azimuth and range information. from the relay station 2. The radar 4 at. the control station I- servesto determine the azimuth, elevation` and range of the. relay stationA 2. relativer to the ground site. The radar 4 alsoserves to apply control to the missile 3 by means of variations. in thepulse recurrence rate of` its control signal.

The position of` the missile 3 with respect, to the ground station` IA is determined. by a plotting method using the interrelations among the ground control station I, the relay station 2 and the missile 3- that are; indicated in Fig. 2 of the accompanying drawing and by the-usual application of trigonometricalV relations that are involved. Radar at the ground control station I: is

used to determine the angles of azimuth and of elevation of the. relay station 2 with respect to the control station I. Theangle of azimuth is the azimuth: of the relay 2 from the missile: 3. The altitude of the missile 3 isS controlledv by an altimeter therein. rfhe. range.- I'l between the missile 3 and thel rela-y 2v is determined by the interrogator I3 on the missile 3- and:y is relayed by the means that have been described to the control station I. 'llhe range 21 between theA control station I andtherela-y 2 is determined by'radar'll at the control station in the usual way.

A preferred circuit for use inthe coding ofv azimuth readings on aradar. pulse emitted from the interrogator i3 on the missile 3 and comprising a part of the present invention is shown in` block diagram form inv Fig. 3 of the accompanying drawings.

In the system that is contemplated hereby, indication of azimuth is transmitted' by a pair of coded pulses, an initial radar pulse followed in a very short time interval by a follower pulse. The separation of the initial pulse from the follower pulse is equated with the azimuth plus a constant.

In the circuit that is shown in Fig. 3 of the drawings, a trigger causes a modulator 2| to pulse a transmitter 22. Signal from the transmitter 22 is fed through a TR. box 23 to a radar antenna 24 and forms the initial pulse referred to above. At the same time the pulse is fed from a, terminal t on the modulator 2| through a constant short time delay network 25 to an azimuth coder 26. A delay transmission line in the coder 26 is provided with a continuously sliding arm 21 that is geared directly to the dish of the interrogator I3 on the missile 3. The delay transmission azimuth coder 26 is arranged to rotate in such a fashion that the point N thereon corresponds to north on a magnetic compass. The magnetic compass monitors the N point to keep it oriented to the north through the motor 28.

operatively, when the dish of interrogator I3 points true north, there is no or zero transmission delay introduced between the beginning of the transmission delay line and a pickoi contact X that is geared to the radar dish. The arc between the pickoif contact X and the point N is the angle that is shown in Figs. 2 and 3 of the drawing. As the dish of interrogator I3 rotates in increasing azimuth, an increasing length of the transmission delay line is introduced between the point N and the pickoff contact X. The pulse from the pickoff contact X is delayed more and more and is fed to the modulator 2| and produces the delayed pulse, which is the follower of the pair of pulses referred to above. 'I'he follower pulse so produced, with its time relation to the initial pulse, supplies the azimuth code.

A blanking system for the circuit is provided by a small delay line 30 and a. flip-flop blanker 3| that are in series between the pickoif contact X on the delay transmission line in the coder 26 and the modulator 2|. The blanking system so provided prevents the delayed pulse mentioned above, after travelling through the delay system and the modulator 2| from initiating a still further pulse, and in turn a continuous group of pulses. The delayed pulse, after a slight delay that is introduced by the small delay line 30 network and that is required to allow the transmitter 22 to send the coded pulse, operates the iiip-iiop blanker 3| circuit. The iiip-iiop blanker 3| blanks the modulator 2| for a period that is equal to the total transmission time of the delay assembly of which the azimuth coder 26 forms a part.

The interrogator circuit is provided with a mode switch 32 that has automatic operation for changeover and means providing for triggering a next pulse from a received pulse. Since the F2 beacon on the relay station 2 does not transpond the azimuth pulse, only one pulse is received by the receiver 5 of the control station The mode switch 32 is a two position switch. At position a the mode switch 32 connects in series an oscillator 33 through a receiver 34 to the TR box 23. At position b the mode switch 32 connects the trigger 20 in series with the receiver 34 and the TR box 23.

A presentation of the pulse envelope that is emitted from the antenna 24 of the circuit that is shown in Fig. 3, is shown in Fig. 4 of the drawings. It will be noted that the pulse envelope that is radiated by the circuit in Fig. 3 comprises a square wave of pulsations that are spaced a linear distance that is equal to the sum of a constant and the product of a second constant and the arc between X and N on the delay transmission line of the coder 26.

A modified system foi use in relaying azimuth code from the F2 frequency beacon to the ground control station is shown in Fig. 5 of the drawings. Whereas in the previously described relay station 2, the beacon |I on frequency F2 supplies the azimuth code to the F1 transpondor I0, in the modification here presented the F2 transpondor transponds the azimuth code on F2 frequency to the receiver 5 at the ground control station i. With this arrangement the coded pulse signal from the F2 transpondor II is prevented from causing the F2 transmitter I3 to repeat the second received pulse as well as the coded pulse that is generated in its own circuits.

In the circuit that is shown in Fig. 5, the components that are common to both Figs. 3 and 5 bear corresponding numerals that are primed in Fig. 5 and not in Fig. 3. In the modified circuit shown in Fig. 5 the flip-flop blanker 3| is connected in series between the terminal t on the modulator 2| and the receiver 34. In the circuit so modified the first retransmitted pulse blanks the receiver 34 so that the second pulse will arrive at the receiver during the time during which it is blanked and will not cause an additional pulse to be triggered. The other circuit components function substantially as shown in Fig. 3.

A circuit for decoding azimuth code in the present invention is shown in Fig. 6 of the accompanying drawings wherein signals that are intercepted by an antenna assembly 36 are fed from a receiver 31 to a gate circuit 38 which feeds. the front pulse of the coded pair to the azimuth indicator 39. An angle indicator 40 on the coder 39 is operated by a motor 4|. The front pulse of the coded pair is delayed by a time that corresponds to the position of the angle indicator 4i) relative to the beginning of the delay transmission line in the azimuth indicator 39. The front pulse of the coded pair then goes to the amplifier 42. The second pulse of the coded pair is fed directly to the ampliiier 42 but in reversed polarity as indicated in Fig. 7 of the drawings. Both pulses pass thru the by-passed tube components 43 and 44 to nip-flop circuits 46 and 41 respectively.

Each pulse trips a corresponding nip-flop circuit 46 and 41. The signal output from the positive iiip-lop 46 and the negative flip-flop 41 are fed to the ampliiiers 48 and 49, respectively, that are connected in push-pull. Signals from the amplifiers 48 and 49 are fed to the grids of the mixers 50 and 5|, respectively. The output of the mixers 5I) and 5| is equal to the algebraic sum of the outputs from the positive and negative iiip-.fiop circuits 46 and 41, respectively, substantially as presented in Figs. 8 and 9 of the drawings. The resultant pulse is proportional in length to the difference in position of the wiper on the angle indicator 48 and that correct position of the wiper on the indicator 40 which produces a zero pulse. The correct position of the wiper is that at which the delay introduced into the front signal by azimuth indicator 39 equals the delay of the second pulse behind the front pulse.

The pulse from the mixers 50 and 5| is fed to a pulse lengthener 53 and thence to the field of agenerator 553. The pulsemaybe-ofY either sign and the: genera-tor voltage' is: polarized accordingtothesign or the. pulse; The generator 55I drives the. motmr` 41 which rotates the Wiper on the angle indicatorV 401.. In this manner the motor that drives the Wiper on, the angle indicator 40 receiyes4 voltage to rotate the wiper until the net pulse; out of themixers 511 and 5I is zero. The angle indicatorY 40rthen, correctly decodes the azimuth indication off the; double pulse signal.

The flip-dop circuits 46 and 41 do not return toA their normal stateuntil the timer circuit 5tL supplies an impulse. The nip-nop circuits 46' and 41 then returnz to zero output after a time that determined by'a delay-line 51 which feeds the timing circuiti 56. from` theugate 38 and termination. 58 of the azimuth indicator or coder 319-.

The systemrthatisihere considered may be disposed at, the site of the ground control station I! or can be used in thev relay station 2v to,Y decode the. F2 frequency'.

Where the system. is positioned aty the relay station 2, a; second delay line 512" and angle indicator slider A0?" would: be provided to code the pulses ofl the F1 frequency beacon, as shown in fra-gruen.taryT circuit form. in Fig. 10- of the drawings. TheA circuit components that correspond to the circuit components that are shown in Fig. 6 are primed in Fig. 10'ior easeof association therewith. In this adaptation the` sliding arma 410- applies theV signal F1, as delayed by the delay line 521" to the amplifder t2', and the sliding-farmlw" applies the signall F2,4 as delayed by the delay line 51 to the same amplifier 62'. In other' component details and for the completion thereof, the circuitvthat is-` shown in Fig. 1-0. comprises andy functions substantiallyasV that shown in Fig. 6;

It is to be understood that the system and the circuits and componentsl that have been disclosed and describedv herein have been submitted for the purposes. of illustrating and describing suit'- ably operating embodiments o the present inyentionand. that. similarly functioning modifications, alterations, changes and substitutions may be made therein Without departing from the scope oi the presentinyention as defined by the appended claims.

What I claim is:

1-. A, radio system of the character described, comprising in combination a control station, a missile adapted for independent. flight, a relay station that is separable from said missile and together therewith adapted. for being launched from the site said control station, and means at said controlstation for directing-:thru said rela-y station the course ot iiight ofsaid missile after beingn separated fromsaid relay station.

2. A radio system, of the character described, comprising inY combination a control station, a missile adapted for independent ight, a relay station that isseparable from said missile, means for maintaining said relay station supported in the air after the separation of the missile therefrom, and means operable` from said control station for directing the flight path of said missile.

3.r A. radio system of the character described, comprising in combination a control station, a pair of radar antenna systems at said control station, an airborne relay station, a missile separable from said relay station, means for supporting. said relayv station, a transpondor beacon on frequency F1 at said relay station and adapted for maintaining communication with both said control station and said missile, a transpondor beacon on irequencyflz at said relay station and adapted for maintaining communication With both said control station and said missile, aL receiver on frequency F1 on said'l missile for communication thru said relay station with one of said radar antenna systems at said control station, and an interrogator on frequency F2 on said missile for communication thru said relay station with one of said. radar antenna systems. at said` control station.

4. A radiosystemA ot :the character described, comprising in. combination a control station, a relay station. carrying missile controllable in flight from said control station and adapted for liberating the relayy station therefrom in night, means. for supporting said relay station, and a radio circuit. in said relay station reporting to `and controlling from` said control station the position and course; of ight of the missile subsequent toits separation from. said relay station.

5.,. A. radio, system for the remote` control of an object in iiight comprising in combination. a control station, a relay station,` and an objectadapted for independent flight after its separation from said, relay station,A a radar on frequency F1 at said control station av receiver on frequency F2 at the control station, a receiver on frequency F1 at the object, an interrogator on frequency F2 at the object, a relay station, carried beacon on frequency F1 for maintaining signal withl the control station radarA andthe object receiver, and a relay station carried beacon on frequency F2 for maintaining signal with the control station receiver and the object interrogator.

6. A remote control vradar system comprising in combination al ground station, an airborne relay radar station, means at said ground. station for determiningl the location of said' airborne relay radar station With respect to said ground station,` a self .propelled airborne, object, instrumentalities at said airborne relay radar station for determining thelocation of` saidI object with respect to said airborne relay radar station and for transmitting said location to said ground station, and means, at said ground station for 'combining an indication of the location of said object as transmitted from said airborne relay radar station with signals from said location udetermining means corresponding to the determined location of said airborne relay radar sta.- tion to derive therefromA the location of said object with reference to said ground station.

EVERARD M. WILLIAMS. l

References Cited in the file of this patentY UNITED STATES PATENTS Number Name Date` 1,945,952 Nicolson Feb. 6,1934 2,176,469 Moueix Oct., 17, 1939 2,252,083 Luck "Aug, 12, 1941 2,301,929l Budenbom "Nov, 17., 1942 2,369,268 Trevor Feb. 1.3, 1945 2,412,670 Epstein Dec. 17, 1946 2,431,016 Bailey et. al. Nov. 18, 1947 2,448,007 Ayres` Aug. 31, 1948 2,582,971 Dunmore Jan. 22, 1952 Number Country Date 358,972 Great Britain Oct. 16, 1.931 

